Rediscovering Michael Wacha’s changeup

All things considered, Michael Wacha probably receives more flak from St. Louis Cardinals fans than he is actually warranted. At the same time, he is partly to blame for the magnitude of these reactions considering his highly successful burst onto the scene in the second half of the 2013 season — one year removed from being drafted 19th overall out of Texas A&M. After convincingly staving off elimination against the Pirates in the National League Divisional Series, the rookie right-hander was awarded National League Championship Series MVP honors for his sterling performance versus a potent Dodgers lineup: two starts, 13.2 innings pitched, zero runs allowed.

Considering Wacha doesn’t turn 26 years of age until July 1st, it isn’t necessarily fair to say his MLB career has already peaked, but given his persisting shoulder problems (while maintaining the exact same mechanics), that certainly feels like a possibility. Yet, for as down as I appear to be on Wacha (and yes, I still think his cutter is garbage), I have not yet given up hope on the 6’6” righty. Why? Because I still believe he possesses the makings of two above-average to plus pitches in the fourseamer and changeup. Since I’ve already written about his (lack of) fourseamer command, let’s take a closer look at his changeup, also known as the pitch that will “make him a lot of money.”

Before I get into the changeup’s details, I first have a confession to make. Out of admitted laziness, I’ve broadly attributed Wacha’s diminished success with the changeup to poor fastball command and hitters being provided with better scouting reports of his repertoire. While both points are undeniably true, I was taking the easy way out as I failed to acknowledge that there may, too, have been a change (pun intended) to the guts of the pitch. To put it another way, when we talk about a pitcher’s fastball no longer working, we take the time to look into its specific PitchF/x data, instead of simply blaming its ineffectiveness on another one of his pitches — the exact error I have committed regarding Wacha’s changeup.

Sure, blaming the ineffectiveness of a changeup on a pitcher’s fourseamer makes sense because one works off the other, but the actual guts of the changeup still matter as well. When I talk about guts, I mean things like location, spin rate, dragless horizontal movement (with a negative number indicating arm-side run in RHPs), and perceived velocity. So, how did the pitch look in 2016 compared to 2015? Let’s start with what I consider the most important aspect of pitching:

Location, location, location

As you can see, Wacha’s changeup location was much more refined in 2015 than it was in 2016. In fact, the pitch’s location heat map in 2015 is borderline ideal — down/inside to righties and down/away to lefties. Understandbly, the pitch strays outward from its core, but the vast majority remains on the left-side of zero (x-axis) meaning Wacha did a good job at avoiding the middle of the plate. In 2016, the core is noticeably looser, and one of its densest locations is only one deviation from being middle-middle — an undesirable location no matter how good a pitch may be.

Beyond location, let’s now take a look at what Statcast and BrooksBaseball.net have to say about the pitch because these are inherent factors in determining location. Remember, Statcast didn’t begin its public roll out until the 2015 season, so unfortunately we do not have data for the 2013 and 2014 seasons. Yet, considering it was an effective pitch for him in 2015, with a very similar sample size to 2016, we can still at least begin to learn a few things from our findings.

Spin Rate

Full disclosure, I am still getting acquainted with the intricacies of spin rate as what is desirable is different for every pitch, and it even varies between pitchers. If this is a topic of interest for you, Eno Sarris and Mike Petriello do great work on the matter, so I strongly recommend following their updates. One thing I do know, though, is that the lower the spin on a changeup, the lower it tends to fall in the zone.

Thus, before looking back at the spin rate column of the table, let’s revisit the changeup heatmaps embedded above. In 2016, Wacha’s core strayed upward toward the ever dangerous middle-middle. And sure enough, Wacha’s spin rate in 2016 (1700) averaged almost 200 RPMs higher than where it was in 2015 (1508). Thus, the year in which his spin rate was up (2016), the resulting location was also up. Now, I don’t yet know how pitchers can consistently harness their respective spin rates, but I’d have to believe a large part has to do with grip. Here’s to hoping Wacha can pull an Adam Wainwright and resort to one of his own changeup instructional videos — if such a video even exists.

Dragless horizontal movement

For whatever reason, I’ve always seemed to focus on the horizontal movement of changeups. Downward movement obviously matters, but to me, a lot of this comes natural — especially from a 6’6” pitcher like Wacha. Plus, my infatuation with Carlos Martinez’s screwball-like changeup is probably to blame for my focus on horizontal movement, but logically, it makes sense. Possessing a pitch that runs away from lefties and into righties leads to swings and misses along with weak contact.

Well, as you can see in the table, Wacha’s changeup averaged two fewer inches of horizontal movement in 2016 (-7.5 inches) than 2015 (-9.56 inches). As I suggested with spin rate, I think a big part of horizontal movement is grip (but also arm action). If Wacha can find that pre-2016 grip and arm action, he very way may return to form in both spin rate and horizontal movement. On a positive note, Wacha appears confident with the pitch’s progress this spring.

Perceived velocity

Perceived velocity is a new Statcast measure that takes into account the pitcher’s stride toward home along with release point in hopes of getting a better grasp of what the batter experiences in the batters’ box. Wacha’s perceived velocity declined considerably from 2015 (88.05 MPH) to 2016 (86.28 MPH). If he experienced more horizontal movement as a result of the decline in velocity, then this would probably be fine, but as stated above, this was not the case. Yes, Wacha also experienced a decline in fourseamer velocity, but the decline didn’t match up perfectly as the changeup drop outpaced the drop of the fourseamer, slightly

The results

The final measure I’ll bring up is launch angle, as the other three (exit velocity, batting average, slugging percentage) are self-explanatory. A launch angle of 10-25 degrees is classified as a line drive. Hitters want to hit line drives, while pitchers want to avoid giving up line drives. Well, in 2016, the average launch angle against Wacha’s changeup was knocking on the door of a line drive. To nearly average a line drive versus a pitch is troubling, especially considering the average launch angle against the pitch in 2015 was a less damaging 4.5° (anything less than 10° is classified as a ground ball).

Bottom line

No, I don’t have a “quick fix” for Wacha going forward, and as I said in the beginning, we are probably too overly critical of him in the first place. He “is what he is,” and given his shoulder health, I’d expect no more than 100-120 innings of average to above-average performance. However, if he is able to rediscover his changeup — something I hope to have demonstrated that he lost a bit last season — he could very easily crack the arbitrary ceiling restriction I’ve placed on his projection. Let’s hope his spring confidence in the pitch is real and not just the usual optimism associated with spring training baseball. It is the pitch that will make him a lot of money after all.

Credit to baseballsavant.mlb.com and brooksbaseball.net for data used in this post.